Single-phase three-level rectifier with hybrid T-shaped bridges

Abstract

A single-phase three-level rectifier with hybrid T-shaped bridges comprises two groups of T-shaped bridges and two split capacitors C1 and C2. Three bridge arms of the two groups of T-shaped bridges are respectively composed of two diodes and a group of bidirectional power tubes; the first T-shaped bridge comprises diodes D1, D2, D5, D6, D7 and D8 and a power switch tube S1, wherein the diodes D5, D6, D7 and D8 and the power switch tube S1 form a group of bidirectional power tubes. The second T-shaped bridge comprises diodes D3 and D4 and power switch tubes S2 and S3, wherein the power switch tubes S2 and S3 form a group of bidirectional power tubes. According to the single-phase three-level rectifier with the hybrid T-shaped bridges, the harmonic content in a power grid is reduced, and the power factor of equipment is greatly improved.

Description

technical field [0001] The invention relates to a three-level rectifier, in particular to a single-phase three-level rectifier of a hybrid T-bridge. Background technique [0002] With the rapid development of power electronics technology, it is urgent to find a new power converter topology in the field of power conversion, so as to improve the voltage level and power factor, while reducing power loss and hardware costs. The traditional two-level rectifier introduces a step-up chopper circuit between the uncontrolled rectifier circuit and the filter capacitor. When the grid voltage is lower than the load voltage, this rectifier will cause large fluctuations in the grid current and inject a large number of harmonics into the grid. At the same time, during the rectification process, the grid current cannot follow the voltage change, which greatly reduces the power factor of the equipment in this mode. At the same time, because of the withstand voltage level of the power elect...

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Problems solved by technology

When the grid voltage is lower than the load voltage, this rectifier will cause large fluctuations in the grid current and inject a large number of harmonics into the grid

At the same time, during the rectification process, the grid current cannot follow the voltage change, which greatly reduces the power factor of the equipment in this way

At the same time, because of the withstand voltage level of the power electronic device itself and the large bus voltage value distributed to each power electronic device by this rectifier, this traditional two-level rectifier is not suitable for high-voltage, high-capacity power applications.

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